Automatic regulation of arc lamps



Jan. 9 K. VESELY ET AL AUTOMATIC REGULATION OF ARC LAMPS Filed March 27,1926 Q F/"g, Z,

45 4.95 u a I K, 40 n 55 WITNES s; F/ ,3. INVENTORS 57 55 g Karel Vase/y2 Kare L usf/g ATTORNEY Patented Jan. 11, 1927.

UNITED STATES KAREL VESELY AND KAREL LUSTXG, GF PRAGUE, CZECHOSLOVAKIA.

AUTOMATIC REGULATION OF ARC LAMPS.

Application filed March 27, 1926, Serial Na. 9

This invention relates to automatic rogulation of are lamps and hasamong its objects the provision of improved means and method forautomatically maintaining the light source, which is located in thecrater formed in the end of the positive electrode of the lamp, in apredetermined position with respect to the co-operating parts of the mp-7 The devices used heretofore for the regula tion of the position of thelamp carbons, in particular the location of the crater, have beendesigned either on the optical or thermal principle. The light emanatingfrom the positive electrode was concentrated by a lens upon a suitablethermometer, which in turn controlled the circuit for moving thepositive carbon. Other regulating devices used selenium for controllingthe movement of the carbon.

The foregoing regulating arrangements are o'versensitive or have toomuch inertia, or hysteresis, resulting in either too quick or too slowregulation, and have proved unsatisfactory.

According to the present invention the movement of the positive carbonand the location of the light source associated witl the crater thereof,is regulated by means of an auxilar electrode which is held in apredeterminet point in space, and so arranged that the voltage betweensaid electrode and the arc electrode that is to be regulated, is appliedto so control the movement of said are electrode as to maintain thecrater portion at the end thereof at a predetermined point in space, asdefined by the location of the auxiliary electrode. The particularfeature of the invention is the arrangement whereby the auxiliaryelectrode, which is usually being consumed by the are adjacent thereto,is so automatically fed that its end is always located in the sameregulating position in the space so that the crater will always belocated in the desired position with respect to the parts of the arclamp with which it is to cooperate.

The foregoing and other objects of the invention will best be understoodfrom the accompanying drawings in which Fig. 1 is a diagrammatic view ofan arclamp regulating system to which our invention may be applied.

Fig. 2 is a view similar to Fig. 1 showing a modification of saidregulating system;

8,043, and in Czechoslovakia January 6, 1925.

Fig. 3 is a diagrammatic, plan view of an arc regulating systemembodying our invention; and,

Fig. 4-. is a side view of a part of the mechanism shown in Fig. 3.

Referring to Fig. 1, an arc lamp has a positive electrode 1 and anegative electrode 2 fed by means of suitable feeding mechanisms 3 and 1to maintain an arc therebetween.

As pointed out above, it is important that the portion of the are whichconstitutes the source of the light, that is, the crater 5 in thepositive electrode, shall be stationary in space, that is, shall bedefinitely located with respect to certain stationary parts of the lampwith which it it is to co-operate. It is an object of the presentinvention to provide means whereby the mechanism 3 which feeds thepositive electrode 1 as it burns off in the arc, shall be so regulatedthat said light source, or crater, shall continuously remain in the sameposition in space, it'- respective of the consumption of the electrodein the arc.

To this end we place near the point where the crater (3 is to belocated, an auxiliary electrode 7 and energize with the voltage dropbetween said electrode and the anode 1,

."ting devic 10 which is shown as sin a relay 11, connected between the7 electrode 7 and the anode 1. The cner m tion of the relay 11 controlsthe closure of Contact members 12 in a circuit 13 which serves toenergize and operate the anode feeding mechanism As is well known, themajor portion of the arc voltage is concentrated near the crater 5, andaccordingly, when the carbon 1 burns off and the crater recedes backfrom the space where it is intended to be mounted, a relatively highvoltage will be applied through the auxiliary electrode 7 to the relay11, closing the contacts 12 in the circuit 13, which energizes the anodefeeding mechanism 3, thus causing the anode to be advancet toward theposition where the crater en led to be held. As soon as the posi- 3011 lis driven so far toward negative electrode 2 that it touches the end ofthe auxiliary electrode 7, there will be substantially no voltageapplied to the relay coil 11, the contacts 12 in the energizing circuitof the feeding mechanism 3 will be opened and the node feeding will bestopped.

As soon as the anoee terminal has burned off a ain, the feeding cyclewill repeat itself as before.

The regulating action of the anode movement described above dc enos onthe correct positioning of the end 0 electrode '7, and the en ess wouldbecome inen' electrode would slowly are near which i; d mused. isparticularly concerned i" setting the consumption of 1 means for oilsaidauxiliary electrode, and thus securing enective control of the locationof the anode crater.

is shown in ig. i we ma provide to this end, in addition to themechanism for feeding the anode 1, a mechanism 21 for feeding theauxiliary electrode i, and regulate said mechai by means of regulatingdevice simian to at employee. for regulating the anode feeding device.The regulating mechanism comprises a relay 23 which is conn cted betweenth auxiliary electrode '7 and the anode l. The relay opens and closes apair of contacts Ql which controls the energization oi the auxiliaryelectrode feeding mechanism 2i.

The relay j is so ed that in case the auxiliary electrode is in contactwitn the positive carbon 1, or with the arc, the contacts 2iare openedand the feeding mechanism 21 of the au liary electrode is deenergized.is soon as the auxiliary electrode l' is consumed by the arc to such anextent that it ceases to be in direct contact with either the positivecarbon or the arc, the relay closes the contacts tl'icreby energizingthe lice g mechanism 21 and advancing the auxxaryeleetrode 1' untilcontact with the are or the carbon is again established.

It is thus possible to compensate the eiiectof the burning ell or theauxiliary electrode and obtain close regulation of the position of thecrater just as if the auxiliary electrode were of a material that is notconsumed by the are.

In the preferred embodiment of our invention shown in P s. and l, wehave shown an arrangeme which compensates for the consumption of theauxiliary electrode on which the regulation of ti e anode movementdepends, with a still higher accuracy than the arrangement shown in Fig.2. In addition, the preferred arrangement has special provisions forreducing the amount of consumption of the au iary electrode to aminimum, while at the same time obtaining the full regulat ng eiicctthat can be secured therefrom. in the improved arrangementol Fig. thetip of the auxiliary electrode 7 is not held continuously near thecrater and the are, but is given a swinging cyclical movement indicmedby the dotted curve 31, 32, 33, that is, the auxiliary electrode 7 iswithdrawn from the point 31, which corresponds to the point at which itis to exercise the regulating action on the anode feeding mechanism, andswung backwardly to the point 32 oi the dotted curve, and then advancedto the point 3-3 until it contacts with the side of the positive carbon1 bacl: of the arc. The auxiliary electrode 7 is then moved back to thepoint 231 and remains there for a short period during which it isconnected to control the anode feeding mechanism, and then the cyclicalmovement along the curve 31, 32, 33, epeats itself in continuoussuccession. \Vhile this cyclical swinging movement of the arc tip of theauxiliary electrode takes place, the electrode is being fed forwardly tothe arc and since it is being brought in contact with the carbon 1 atduring each cycle, this contact thus determines the position of theupper end of the electrode when it is held at 31 near the arc toexercise the regulating action.

In other words, instead of controlling the movement 01 the auxiliaryelectrode 7 toard the are, for compensating the 'consumption of saidelectrode by the are, in response to the variation of the voltage dropbetween the auxiliary electrode and the anode, as in Fig. 2, thearrangement in Fi g. 3 cyclically withdraws the auxiliary electrode fromthe arc and brings the end of said electrode which is to exercise theregulating action into abutment against a point which is lixed in space,and thereby determines the position of the end of said auxiliaryelectrode when it is, at a subsequent moment of the cycle, brought backinto the are for regulating the anode movement.

The special arrangement shown in Fig. 3 for carrying out theabovedescribed regulation of the electrode movement comprises a rockinglever 35 arranged to be swung around pivot 86 at one end thereof. Theother end 37 or the rocking lever is con nected through rod 3b to aneccentric 39 which is driven by a pinion i0 engaging a gear wheel llthat is rotated by a suitable motor not shown in the drawing. The gearll is directly connected to a second eccenter 4-1 which serves to impartthrough a pin and slot connection 443 a swinging movement to anelectrode guide ll thathas at its upper end a pivotal connection ii)with the rocking lever Longitudinally along the electrode guide l-l ismounted a bushing l6 in which is slidably mounted the auxiliaryelectrode 7. The auxiliary electrode is lrictionally held in the bushingThe gear wheel all has also a worm d ive connection l? with a threadedrod which serves to propel upwardly an electrode feed member 49 which isarranged lit) gamers thev arc.

Since the gear wheel 41 has twice as;

manyteeth as the pinion 40', the endrozfi the electrode 7 will drive theswinging move ment: along curve 31, 32, 33 referred to above. On theotherhand, the pitch of the thread on the rod 48 is so, chosen that theupward movement of the electrode propelling member 49 tends to move saidelectrode faster than the rate at which its end is being consumed by thearc. If the vertical position of the auxiliary electrode 7 were fixed,the end of the electrode would, after a certain period, ass the point3-1 which may be regarde as a regulating point. The position of the rodis, however, not fixed. The auxiliary electrode; swings and at a certainpoint of the swinging cycle its end strikes the carbon 1, thus fixingthe end of said carbon, and when the auxiliary rod moves'back to thevertical position, its endisexactly at the regulating point 33,

irrespective of the amount of the burning thereof in the arc. Thecontact with the arc is, therefore positive.

Withthe foregoing arrangement the auxiliary electrode maintains positivecontact with the are, since upon hitting the anode 1 at 33, it movesdown in the bushing to such a position that when swinging back along 33,32 to 31, the end comes exactly to the point 31 at which the regulatingaction is to be exercised.

The circuit which energizes the feeding mechanism of the anode is closedthrough the contact members 53 which are operated by a relay 54, that isconnected between the anode 1 and the auxiliary electrode 7, as in thearrangement shown in Fig. 1. The circuit which energizes the feedingmechanism of the anode has included therein an additional pair ofcontact members 55 and 56, which are closed, circuited by a contactsegment 57 operated by the gear wheel 41 to close the circuit only whenthe auxiliary electrode 7 has its tip at the point 31 during which it isadapted to exercise the regulating action. Through this arrangement, themovement of the positive carbon can take place only during the instantwhen the end of the auxiliary electrode 7 is near the regulating point31 of the arc. This provision prevents the operation of the controlequipment during any other period of the swinging motion of theauxiliary electrode by reason of an instantaneous irregularity of thearc.

In order to prevent danger to the lamp mechanism in case the propellingmember 49 reaches its highest upper position, indicated at 60 by dottedlines, that is, at a time when the auxiliary rod has been burned down tothe shortest admissible length, the lamp is arranged to be automaticallycut out of service by a switch 61 operated by said propelling member 49.

We claim as our invention:

1. In an arc: lamp, a pair of electrodes adapted to. produce an arc,means for feed- ,ing one of said electrodes, an auxiliary electrodeadjacent to the arc tip of said last mentioned electrode, meanscontrolled by the current passing through said auxiliary eleci trode forcontrolling said feeding means,- and means responsive to the operationof said: are for automatically compensatingfor the burning of saidauxiliary electrode.

2. In an arc lamp, a main electrode and an additional electrodeco-operating with said main; electrode for producing an arc, said mainelectrode having a tip required to be located at a predetermined fixedposition with respect to the stationary parts of said lamp irrespectiveof the burning of said tip. by the are, means for feeding said mainelectrode, electro-magnetic means. for bringing into operation saidfeedingmeans, and anauxi-liary electrode adjacent to the tip; of saidmain electrode and in circuit with said electro-magnetic means, saidauxiliary electrode being adapted to engagethe arc to close a circuitthrough said electromagnetic means, and means responsive to theoperation of said are for automatically feeding said auxiliary electrodeto offset the consumption thereof by said are.

3. In an arc lamp, a main electrode and an additional electrode adaptedto co-operate with said main electrode to maintain an. are, means forfeeding said main electrode toward the arc to compensate for theconsumption thereof and maintain the tip of said main electrode at apredetermined point with respect to the stationary parts of the lamp, anauxiliary regulating electrode having its tip engaging said arc, aregulating mecha nism connected between said main electrode and saidauxiliary electrode to regulate the feeding of said main electrode formaintaining the tip of the latter at the aforesaid position, and meansfor periodically withdrawing said auxiliary electrode from the arc andadjusting the location thereof so that the tip of said auxiliaryelectrode is at a pre-fixed point in space with respect to thestationary parts of said lamp when carrying out the regulation of themovement of the main electrode.

4. In an arc device, a main electrode, an auxiliary electrode arrangedto maintain an arc with said main electrode, a mechanism for feedingsaid main electrode into the arc to compensate for the consumptionthereof an auxiliary electrode having a tip adapted to engage said arenear the tip of said main electrode, regulating means connected betweensaid main electrode and said auxiliary electrode to so control saidmechanism in response to the voltage between said auxiliary electrodeand said main electrode as to maintain the tip of said main electrode ata h'xed position with relation to the stationary parts o't said light,and means for peri' odically Withdrawing said auxiliary electrode fromsaid arc.

5. An arrangementas defined by claim 4, characterized by means forfixing the position of the auxiliary electrode while removed from theare so that the tip thereof when in engagement with the arc is at apredetermined fixcd position in spacewith respect to the stationaryparts o't said deyice.

(5. An arrzu ment as deiined by claim el, characterized by means torcausing the end oi said auxiliary electrode to abut against asubstantially fixed point of said device to thereby pre-iix the locationof the tip of said auxiliary electrode when in regulating engagementwith said are.

7. In an arc device, a main electrode, an auxiliary electrode arrangedto maintain an arc with said main electrode. a mechanism for feedingsaid electrode into the are, an auxiliary electrode hayiu a tip adaptedto engage said are near the tip at said main electrode, regulating meansconnected letween said main electrode and said auxiliary electrode forso controlling said mechanism as to maintain the tip of said mainelectrode in a predetermined position with respect to the tip of saidauxiliary electrode when in engagement with the are, means for feedingsaid auxiliary electrode into the are to onset the consumption thereof,and means for locating the tip of said auxiliary electrode in carryingout said regulating action, said means comprising means for withdran ingthe tip of said auxiliary electrode from the are, means for causing saidauxiliary electrode to abut. against a point that is substantially fixedwith respect to said device, and means for returning said tip into thearc to carry out said regulating action.

8. An arrangement as defined by claim 7, characterized oy means forrestricting the 'leeding' movement of the main electrode to a periodduring which said auxiliary electrode is in a predetermined position inspace.

In testimony whereof, We have hereunto subscribed our names this 1st dayof February. 1926.

KAREL VESELY. KAREL LUSTIG.

